Isoelectric Electroencephalography in Infants and Toddlers during Anesthesia for Surgery: An International Observational Study

Ian Yuan*, Ting Xu, Justin Skowno, Bingqing Zhang, Andrew Davidson, Britta S. Von Ungern-Sternberg, David Sommerfield, Jianmin Zhang, Xingrong Song, Mazhong Zhang, Ping Zhao, Huacheng Liu, Yifei Jiang, Yunxia Zuo, Jurgen C. De Graaff, Laszlo Vutskits, Vanessa A. Olbrecht, Peter Szmuk, Charles D. Kurth, Minal MenezesSuzette Sheppard, Zhengzheng Gao, Dongxu Lei, Jijian Zheng, Mengmeng Ding, Panpan Chen, Bin Du, Abhusani Bhuju, Camille Van Hoorn, Emilie Roden, Georgia Georgostathi, Adam Richter, Steve B. Ampah, Jimmy W. Huh, Shih Shan Lang, Richard M. Missett, Matthew P. Kirschen, Alexis Topjian, Paula Hu, Rita Saynhalath, Proshad Efune, Gijo Alex

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

15 Citations (Scopus)


Background: Intraoperative isoelectric electroencephalography (EEG) has been associated with hypotension and postoperative delirium in adults. This international prospective observational study sought to determine the prevalence of isoelectric EEG in young children during anesthesia. The authors hypothesized that the prevalence of isoelectric events would be common worldwide and associated with certain anesthetic practices and intraoperative hypotension. Methods: Fifteen hospitals enrolled patients age 36 months or younger for surgery using sevoflurane or propofol anesthetic. Frontal four-channel EEG was recorded for isoelectric events. Demographics, anesthetic, emergence behavior, and Pediatric Quality of Life variables were analyzed for association with isoelectric events. Results: Isoelectric events occurred in 32% (206 of 648) of patients, varied significantly among sites (9 to 88%), and were most prevalent during pre-incision (117 of 628; 19%) and surgical maintenance (117 of 643; 18%). Isoelectric events were more likely with infants younger than 3 months (odds ratio, 4.4; 95% CI, 2.57 to 7.4; P < 0.001), endotracheal tube use (odds ratio, 1.78; 95% CI, 1.16 to 2.73; P = 0.008), and propofol bolus for airway placement after sevoflurane induction (odds ratio, 2.92; 95% CI, 1.78 to 4.8; P < 0.001), and less likely with use of muscle relaxant for intubation (odds ratio, 0.67; 95% CI, 0.46 to 0.99; P = 0.046]. Expired sevoflurane was higher in patients with isoelectric events during preincision (mean difference, 0.2%; 95% CI, 0.1 to 0.4; P = 0.005) and surgical maintenance (mean difference, 0.2%; 95% CI, 0.1 to 0.3; P = 0.002). Isoelectric events were associated with moderate (8 of 12, 67%) and severe hypotension (11 of 18, 61%) during preincision (odds ratio, 4.6; 95% CI, 1.30 to 16.1; P = 0.018) (odds ratio, 3.54; 95% CI, 1.27 to 9.9; P = 0.015) and surgical maintenance (odds ratio, 3.64; 95% CI, 1.71 to 7.8; P = 0.001) (odds ratio, 7.1; 95% CI, 1.78 to 28.1; P = 0.005), and lower Pediatric Quality of Life scores at baseline in patients 0 to 12 months (median of differences, -3.5; 95% CI, -6.2 to -0.7; P = 0.008) and 25 to 36 months (median of differences, -6.3; 95% CI, -10.4 to -2.1; P = 0.003) and 30-day follow-up in 0 to 12 months (median of differences, -2.8; 95% CI, -4.9 to 0; P = 0.036). Isoelectric events were not associated with emergence behavior or anesthetic (sevoflurane vs. propofol). Conclusions: Isoelectric events were common worldwide in young children during anesthesia and associated with age, specific anesthetic practices, and intraoperative hypotension.

Original languageEnglish
Pages (from-to)187-200
Number of pages14
Issue number2
Publication statusPublished - Aug 2022

Bibliographical note

Funding Information:
The study was supported by a grant (No. 9897) from the Perth Children’s Hospital Foundation, Perth, Australia, and the Society of Pediatric Anaesthetists in New Zealand and Australia (New South Wales, Australia). Masimo Inc. (Irvine, California), provided the Sedline EEG monitors and sensors used in this study.

Publisher Copyright:
© 2022 Lippincott Williams and Wilkins. All rights reserved.


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